March 4, 2009 --
Huntington's disease (HD), also called Huntington's Chorea, is a progressive neurological condition passed down through families through their genes. A child of a person with Huntington's has a 50 percent chance of developing it themselves. The condition is rare, affecting about one in 10,000 people in the United States. Huntington's disease causes brain cells, or neurons, in certain areas of the brain to degenerate, resulting in uncontrollable movements, loss of intellectual abilities and emotional problems. Symptoms of Huntington's normally present themselves when a patient is between ages 30 and 50. Those who show symptoms earlier usually have a more serious case of the disease. According to the National Institution of Neurological Disorders and Stoke, some of the early signs of Huntington's disease include mood swings, depression, irritability, difficulty driving and learning new things. Medications are available to treat the signs and symptoms of HD, but currently, there is no way to stop HD; however, with the discovery of the HD gene a decade-and-a-half ago, researchers are investigating how it causes the disease in the human body, so they can hopefully one day prevent it. In 2006, researchers discovered that the Huntington's gene disturbs the accumulation of cholesterol in the brain. Specifically, the protein expressed by the Huntington's gene interacts with another protein to cause the disruption. Cholesterol is crucial for the communication of brain cells so a change in cholesterol levels or their location can cause problems with motor skills, cognitive skills and speech. Finding a way to target the interaction between the proteins may lead to a targeted drug therapy.
A simple blood test can let people know if they will develop the disease or not, but since there is no cure, many opt not to have it. Patients usually die within 10 to 30 years of its onset.
PUTTING PATIENTS BACK IN CONTROL: As Huntington's disease progresses, many suffer from chorea, or jerky, involuntary movements throughout the body. Tetrabenazine (Xenazine) is the first drug approved by the FDA to treat chorea in HD patients. It works by decreasing the amount of dopamine in the brain. Dopamine is a neurotransmitter that allows certain nerve cells to communicate. In people who have HD, dopamine is overactive, resulting in the abnormal movements. By decreasing dopamine, the movements are thereby also decreased.
A randomized, double-blind, placebo-controlled clinical trial investigated the safety and effectiveness of the drug. The involuntary movements of patients who received tetrabenazine reduced on average by 25 percent. In addition, patients who took the drug were six times as likely to be considered by their doctors to have improved significantly. Sixteen sites across the county conducted the study, which involved 84 patients.
FOR MORE INFORMATION, PLEASE CONTACT:
Deborah Song, Media Relations
Rush University Medical Center